Wood chipper



Oct. 4, 1966 H. J. EKLUND 3,276,700

v WOOD CHIPPER Filed Oct. 25, 1965 2 Sheets-Sheet l INVENTOR.

, Hem/kl Eli/arid L M/ Mf'M A Hamg s Oct. 4, 1966 H. J. EKLUND 3,276,700

WOOD CHIPPER Filed Oct. 25, 1963 2 Sheets-Sheet 2 I INVENTOR. L Henri/1'J. /(/U/?d United States Patent 3,276,700 WOOD CHIPPER Henrik J. Eklund,Pittsfield, Mass., asslgnor to Beloit Corporation, a corporation ofWisconsin Filed Oct. 25, 1963, Ser. No. 318,865 Claims. (Cl. 24155) Thisinvention relates to a wood chipper and more particularly to improvedmeans for continuously removing chips fro-m the chipper as they are cut.

As object of my invention is to provide a wood chipper in which thechips are conveyed therethrough and discharged by a combination offorces consisting of the kinetic energy possessed by the moving chips,the blowing action of a moving stream of air adjacent the chips, and theblowing action of an involute blower.

Another object of my invention is to provide a wood chipper of thecharacter designated in which the wood chips are discharged as fast asthey are brought into the apparatus, thereby eliminating carry-over ofthe chips.

A further object of my invention is to provide a wood chipper of thecharacter designated in which an effective blower is provided withoutthe chips entering the space between the blowing means and the housingtherefor.

A still further object of my invention is to provide a wood chipperwhich shall be simple of construction, economical of manufacture and onewhich is compact and requires a minimum of space for shipment, storageand installation.

Heretofore in the art to which my invention relates various types ofwood chippers have been proposed. However, the chip conveying means forsuch chippers depend almost entirely upon the kinetic energy possessedby the moving chips. While some air is conveyed through conventionaltype wood chippers by radially extending blades therein, which contactthe chips, the air is insufficient for effective removal of the chipsfor the reason that a relatively close clearance is required between theradially extending chip conveying blades and the housing therefor. Thatis, the chip conveying housing is not involute in shape since therewould be a substantial distance between the chip conveying blades andthe housing adjacent the discharge end thereof whereby the chips wouldenter the space between the blades and the housing.

To overcome the above and other difliculties, I provide a wood chipperembodying a rotary disc having angularly spaced knives and passagewaystherethrough, together with means to feed wood to one side of the discwhereby the wood is cut into chips which pass through the passageways tothe other side of the disc. An involute blower housing surrounds theside of the rotary disc adjacent the wood feeding means and a circularchip receiving housing surrounds the other side of the disc. Thecircular chip receiving housing is separated from the involute housingby the disc whereby separate housings are provided at opposite sides ofthe disc. Angularly spaced blades are carried by opposite sides of therotary disc whereby chips are continuously conveyed through the circularchip receiving housing and air is circulated continuously through theinvolute housing. The circular housing is provided with a tangentialoutlet and the involute housing is provided with a circumferentialoutlet, both of which communicate with a discharge conduit whereby theair discharged through the circumferential outlet aids in conveying thechips through the discharge conduit.

Apparatus embodying features of my invention is illustrated in theaccompanying drawings, forming a part of this application, in which:

FIG. 1 is a side elevational view, partly broken away and in section;

3,276,700 Patented Oct. 4, 19(zi6 FIG. 2 is a vertical sectional viewtaken generally along line 22 of FIG. 1;

FIG. 3 is a view taken generally along the line 33 of FIG. 2; and,

FIG. 4 is an end elevational view taken generally along the line 44 ofFIG. 3.

Referring now to the drawings for a better understanding of myinvention, I show a power unit 10, such as an electric motor, having adrive shaft 11. Opposite ends of the drive shaft 11 are supported insuitable bearing members 12 and 13 which in turn are supported by asupporting frame indicated generally at 14. The power unit 10 is alsoconnected to transverse frame members 16 which is turn are connected tothe supporting frame 14.

Mounted on the shaft 11 and adapted for rotation therewith is a rotarydisc 17 having a peripheral flange 18, as shown in FIGS. 1 and 2. Aplurality of angularly spaced knives 19 are mounted at one side of therotary disc 17 and angularly spaced through passageways 21 are providedadjacent the knives whereby wood cut into chips by the knives passesthrough the passageways to the opposite side of the disc.

Surrounding the side of the rotary disc 17 carrying the knives 19 is aninvolute housing 22 having a circumferential outlet 23. A feed chute 24communicates with the involute housing 22 in position to feed woodindicated at W to the adajacent side of the rotary disc 17 whereby thewood contacts the knives 19 and is cut into chips which pass through theopenings 21 to the opposite side of the rotary disc. Surrounding theother side or discharge side of the rotary disc 17 is a circular,chipreceiving housing 26 having a tangential outlet 27.

Secured to the rotary disc 17 in position to rotate within the circularhousing 26 are a plurality of angularly spaced blades 28. As shown inFIG. 2, the blades 28 are adapted to rotate within the circular housing26 with a relatively close fit whereby chips are conveyed therethroughand then outwardly through the tangential outlet 27. The blades 28 aresecured in place by suitable means, such as bolts 29 having nuts 31.

Secured to the rotary disc 17 in position to rotate within the involutehousing 22 are a plurality of angularly spaced blades 32. The blades 32are preferably secured in place by the same bolts 29 which secure theblades 28 in place. That is, the bolts 29 pass through the blades 28,the peripheral flange 18 and the blades 32. Also, the blades 32 arepositioned outwardly of the feed chute 24 whereby the wood does notcontact the blades 32. By providing an involute housing 22, the blades32 move progressively away from the inner surface of the housing 22 asthey approach the circumferential outlet 23. That is, the spacingbetween the blades 32 and the inner circumferential surface of theinvolute housing 22 increases from approximately /2 inch until itreaches approximately 7 inches adjacent the circumferential outlet 23.Accordingly, the involute housing 22 having the fan blades 32 thereinprovides a very efficient 'blower which discharges air through thecircumferential outlet 23.

Communicating with the upper end of the circumferential outlet 23 andthe upper end of the tangential outlet 27 is a discharge conduit 33,whereby the air discharged from the circumferential outlet 23 aids inconveying the chips which are discharged through the tangential outlet27. As shown in FIG. 2, the outer wall of the circumferential outlet 23is directed upwardly and inwardly toward the tangential outlet 27whereby the air discharged therefrom strikes the chips at an angle toprevent channeling of the air.

From the foregoing description, the operation of my improved woodchipper will be readily understood. The wood W is fed into the chute 24whereupon it is cut into chips by the knives 19. The chips pass throughthe openings 21 into the chip receiving housing 2. Since the blades 32are mounted outwardly of the feed means 24, they do not contact thewood, but provide blower blades which circulate air through the involutehousing 22. Air is drawn inwardly of the involute housing 22 by acentrally disposed inlet opening 34 which surrounds the drive shaft 11,as shown in FIG. 2. In like manner some air is drawn inwardly of thechip receiving housing 26 by a centrally disposed inlet opening 36 whichalso surrounds the shaft 11.

The chips are conveyed through the housing 26 by the kinetic energypossessed by the moving chips and the air drawn inwardly through theinlet opening 36. Since the housing 26 is circular, the blades 28 remainrelatively close to the inner circumferential surface of the housing 26,thereby preventing the chips from entering the small space between thehousing and the blades 28. As the chips are discharged from thetangential outlet 27, they are engaged by the air which is dischargedthrough the circumferential outlet 23 whereby this air aids in conveyingthe chips through the discharge conduit 33. It will be noted that thecircumferential outlet 23 is separated from the tangential outlet 27 bya partition wall 37 whereby the air discharged through thecircumferential outlet 23 does not engage the chips until they areintroduced into the discharge outlet 33.

From the foregoing, it will be seen that I have devised an improved woodchipper which is compact in construction and one which utilizes aself-contained blower in conjunction with the kinetic energy possessedby the moving chips to remove the chips continuously from the apparatusin an effective manner. By providing an involute blower housing at theopposite side of the rotary disc from the circular chip receivinghousing, I not only provide an effective blower which aids in conveyingthe chips, but provide a chip receiving housing which is positionedrelatively close to the chip conveying blades therein, therebyeliminating passage of the chips between the conveying blades and thehousing. Furthermore, by providing an involute blower housing and acircular chip receiving housing at opposite sides of the rotary discmember which in turn is mounted on a common shaft with the drive meansfor the chipper, I not only reduce the overall size of the chipper butprovide one which is dynamically balanced and one which requires aminimum of operating parts.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof, and I desire, therefore, that only such limitations shall beplaced thereupon as are specifically set forth in the appended claims.

What I claim is:

1. In a wood chipper embodying a rotary disc having angularly spacedknives and angularly spaced passageways therethrough together with meansto feed wood to one side of the disc whereby the wood is cut into chipswhich pass through the passageways to the other side of the disc,

(a) an involute housing surrounding said one side of said disc,

(b) a circular housing surrounding said other side of the disc andseparated from said involute housing by said disc,

(c) angularly spaced blades carried by said other side of the disc anddisposed to rotate within said circular housing with a relatively closefit to convey chips therethrough,

(d) angularly spaced blades carried by said one side of the discoutwardly of said means to feed wood and disposed to rotate Within saidinvolute housing to circulate air therethrough,

(e) a tangential outlet for said circular housing for discharging chipstherefrom,

(f) a circumferential outlet for said involute housing adjacent andalongside said tangential outlet for discharging air therefrom, and

(g) a discharge conduit communicating with said tangential outlet andsaid circumferential outlet to receive chips discharged through saidtangential outlet and air discharged through said circumferential outletwhereby the air discharged through said circumferential outlet aids inconveying the chips through said discharge conduit.

2. A wood chipper as defined in claim 1 in which the disc is providedwith an annular member around the periphery thereof in position toseparate the outer por tion of the involute housing from the outerportion of the circular housing.

3. A wood chipper as defined in claim 2 in which the radially extendingblades are secured to said annular member.

4. A wood chipper as defined in claim 1 in which the circumferentialoutlet is defined by a conduit having its discharge end directedinwardly toward the tangential outlet whereby air discharged from saidcircumferential outlet contacts the chips discharged through saidtangential outlet at an angle.

5. A wood chipper comprising:

(a) a drive shaft,

(b) bearing members supporting opposite ends of said shaft for rotation,

(c) a motor mounted on said shaft intermediate said bearing members forrotating the same,

(d) a disc mounted on said shaft intermediate said motor and one of saidbearing members for rotation therewith and having angularly spacedpassageways therethrough,

(e) angularly spaced knives carried by one side of said disc adjacentsaid passageways,

(f) means to feed wood to said one side of the disc whereby the wood iscut into chips which pass through the passageways to the other side ofthe disc,

(g) an involute housing surrounding said one side of said disc,

(h) a circular housing surrounding said other side of the disc andseparated from said involute housing by said disc,

(i) angularly spaced blades carried by said other side of the disc anddisposed to rotate within said circular housing with a relatively closefit to convey chips therethrough,

(j) angularly spaced blades carried by said one side of the discoutwardly of said means to feed wood and disposed to rotate within saidinvolute housing to circulate air therethrough,

(k) a tangential outlet for said circular housing for discharging chipstherefrom,

(l) a circumferential outlet for said involute housing adjacent andalongside said tangential outlet for discharging air therefrom, and

(m) a discharge conduit communicating with said tangential outlet andsaid circumferential outlet to receive chips discharged through saidtangential outlet and air discharged through said circumferential outletwhereby the air discharged through said circumferential outlet aids inconveying the chips through said discharge conduit.

References Cited by the Examiner UNITED STATES PATENTS ROBERT C.RIORDON, Primary Examiner.

DONALD KELLY, Examiner.

1. IN A WOOD CHIPPER EMBODYING A ROTARY DISC HAVING ANGULARLY SPACEDKNIVES AND ANGULARLY SPACED PASSAGEWAYS THERETHROUGH TOGETHER WITH MEANSTO FEED WOOD TO ONE SIDE OF THE DISC WHEREBY THE WOOD IS CUT INTO CHIPSWHICH PASS THROUGH THE PASSAGEWAYS TO THE OTHER SIDE OF THE DISC, (A) ANINVOLUTE HOUSING SURROUNDING SAID ONE SIDE OF SAID DISC, (B) A CIRCULARHOUSING SURROUNDING SAID OTHER SIDE OF THE DISC AND SEPARATED FROM SAIDINVOLUTE HOUSING BY SAID DISC, (C) ANGULARLY SPACED BLADES CARRIED BYSAID OTHER SIDE OF THE DISC AND DISPOSED TO ROTATE WITHIN SAID CIRCULARHOUSING WITH A RELATIVELY CLOSE FIT TO CONVEY CHIPS THERETHROUGH, (D)ANGULARLY SPACED BLADES CARRIED BY SAID ONE SIDE OF THE DISC OUTWARDLYOF SAID MEANS TO FEED WOOD AND DISPOSED TO ROTATE WITHIN SAID INVOLUTEHOUSING TO CIRCULATE AIR THERETROUGH,